VENTS TwinFresh Smart House Connection Guide

Purpose

This guide covers the connection of TwinFresh Expert RW V.2 (V.3) and TwinFresh Style Wi-Fi series of air handling units to a "Smart House" system. Control is provided only by Master devices. Slave devices, mobile devices, and “Smart House” system components are connected to master devices over Wi-Fi. Slave devices are controlled by means of commands received from master devices.

There are two wireless connection patterns available:

1. A master device with a Wi-Fi access point, which can accept up to eight slave connections. If all available eight connections of the master device are used, a mobile device or a "Smart House" system will not be able to connect to the master device.
2. Master devices, slave devices, mobile devices and a “Smart House" system connect to the Wi-Fi access point of the network router. In this case, the maximum number of available Wi-Fi connections is limited by the router functionality. If the number of necessary ventilation units is more than the router can accept, you may use an additional Wi-Fi access point to connect the remaining ventilation units. The router network may include several master devices to provide control by zones.

The connection is set up via the mobile application from the Connection -> Wi-Fi setup menu (see the unit data sheet).

Network Parameters

Data is exchanged via the UDP protocol (with broadcast support).

Master device IP address:

• 192.168.4.1 if the master device runs without a router (connection pattern 1).
• If the master device is connected via a router (connection pattern 2), the IP address is set up via the mobile application (see unit data sheet) and can be defined as static or dynamic (DHCP).

Master device port:

Maximum packet size:

Packet Structure

The general packet structure is as follows:

0xFD 0xFD TYPE SIZE ID ID SIZE PWD PWD FUNC DATA Chksum L Chksum H

• 0xFD 0xFD: packet beginning character (2 bytes).
• TYPE: protocol type (1 byte). Value = 0x02.
• SIZE ID: ID block size (1 byte). Value = 0x10.
• ID: controller ID. This number is printed on the label (16 characters) applied to the control circuit board or the unit casing. You can also substitute the ID with "DEFAULT_DEVICEID" code word. The ID can be used:
  • To control the master device if it runs without a router (connection pattern 1).
  • To search for master devices on the network if a router is used (connection pattern 2). In this case, the device will respond to two parameters only: 0x007C and 0x00B9 (see parameter table).
• SIZE PWD: PWD block size (1 byte). Possible values: from 0x00 to 0x08.
• PWD: device password (permissible characters: "0...9", "a...z", and "A... Z"). The default password is "1111". This password can be changed via the mobile application from the Connection -> At home -> Settings menu (see the unit data sheet).
• FUNC: the function number (1 byte). It defines the action with the data and the DATA block structure:
  • 0x01: parameter read.
  • 0x02: parameter write. The controller does not send any response regarding the status of the given parameters.
  • 0x03: parameter write with subsequent controller response regarding the status of the given parameters.
  • 0x04: parameter increment with subsequent controller response regarding the status of the given parameters.
  • 0x05: parameter decrement with subsequent controller response regarding the status of the given parameters.
  • 0x06: controller response to the request (FUNC = 0x01, 0x03, 0x04, 0x05).
• DATA: data block. It consists of parameter numbers and their values:
  • If FUNC = 0x01 or 0x04 or 0x05: P1 P2 Pn
  • If FUNC = 0x02 or 0x03 or 0x06: P1 Value 1 P2 Value 2 Pn Value n
  Parameter numbers (see parameter table) consists of two bytes (the high byte is virtual). By default the high byte of each parameter number in each new packet equals 0x00. The high byte can be changed within a single packet using the special 0xFF command (see below).
• P is the low byte of the parameter number. Possible values: 0x00 – 0xFB. The 0xFC – 0xFF values are special commands:
  • 0xFC: change function (FUNC) number. The following byte must be the new function number ranging from 0x01 to 0x05. This command is used to organise several functions with different actions into a single packet.
  • 0xFD: parameter not supported by the controller. The following byte is the low byte of the non-supported parameter. This command is used in controller response (FUNC = 0x06) to a non-supported parameter read or write request.
  • 0xFE: change a size of the Value for one parameter which follows. The following byte must be the new parameter size followed by the low byte of the parameter number, and then - by the Value itself.
  • 0xFF: change the high byte for parameter numbers within a single packet. The following byte must be the new high byte.
• Value: parameter value (the default size of value is 1 byte). Byte ordering from least significant byte to most significant byte.
• Chksum L | Chksum H: checksum (2 bytes). This is calculated as the total of bytes beginning with the TYPE byte and ending with the final byte of the DATA block.

Examples of Using Special Commands in the Data Block

Write request (FUNC = 0x03) for parameters number 0x009B, 0x0070, and 0x0007

0xFD 0xFD 0x02 0x10 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x04 0x31 0x31 0x31 0x31 0x01 0x01 0x02 0xDE 0x00

Write request details:

• Parameter 0x009B to be assigned the value of 0x02.
• Parameter 0x0070 to be assigned the value of 0x42378504. The value size is 4 bytes as indicated by the special command 0xFE + 0x04.
• Parameter 0x0007 to be assigned the value of 0x01.

Controller response (FUNC = 0x06) to write request

0xFD 0xFD 0x02 0x10 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x04 0x31 0x31 0x31 0x31 0x06 0x01 0x00 0x02 0x42 0x37 0x85 0x04 0x07 0x01 0xE6 0x00

Controller response details:

• Parameter 0x009B equals 0x02.
• Parameter 0x0070 equals 0x42378504. The value size is 4 bytes as indicated by the special command 0xFE + 0x04.
• Parameter 0x0007 equals 0x01.

Read request (FUNC = 0x01) for parameters number 0x0101, 0x0104, and 0x0240

0xFF 0x01 0x01 0x04 0xFF 0x02 0x40 0x01 0x01 0x04 0x05 0xFF 0x02 0x40 0x51 0x68

Controller response (FUNC = 0x06) to write request

0xFF 0x01 0xFD 0x01 0x04 0x05 0xFF 0x02 0x40 0x51 0x68

Controller response details:

• Parameter 0x0101 is not supported by the controller as indicated by the special command 0xFD.
• Parameter 0x0104 equals 0x05.
• Parameter 0x0240 equals 0x6851. The value size is 2 bytes as indicated by the special command 0xFE + 0x02.

Complete Packet Examples

Sending "Smart House–> Controller" packet

This packet contains a read request (FUNC = 0x01) for parameters number: 0x0001, 0x0002.

0xFD 0xFD 0x02 0x10 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x04 0x31 0x31 0x31 0x31 0x01 0x01 0x02 0xDE 0x00

Request details:

• Checksum: 0x00DE.

Sending "Controller –> Smart House" packet

This packet contains the controller response (FUNC = 0x06) to the write request.

0xFD 0xFD 0x02 0x10 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x04 0x31 0x31 0x31 0x31 0x06 0x01 0x00 0x02 0x03 0xE6 0x00

Controller response details:

• Parameter 0x0001 equals 0x00.
• Parameter 0x0002 equals 0x03.
• Checksum: 0x00E6.

Parameter Table

Functions: R - 0x01, W - 0x02, RW - 0x03, INC - 0x04, DEC - 0x05

*Available for all models except TwinFresh Expert RW-30 V.2

**Available for TwinFresh Expert RW1-50 V.3, TwinFresh Style Wi-Fi, TwinFresh Style Wi-Fi Frost, TwinFresh Style Wi-Fi mini.

Example of Processing Packets Written in C

The following C code demonstrates how to process incoming and outgoing packets for the Smart House system.

// Special commands
#define BGCP_CMD_PAGE 0xFF
#define BGCP_CMD_FUNC 0xFC
#define BGCP_CMD_SIZE 0xFE
#define BGCP_CMD_NOT_SUP 0xFD

// Special commands
#define BGCP_FUNC_RESP 0x06

uint8_t receive_data [256];
uint16_t receive_data_size;
uint8_t State_Power;
uint8_t State_Speed_mode;
char current_id [17] = "002D6E1B34565815"; // Controller ID

// Checksum and start of packet check
uint8_t check_protocol (uint8_t *data, uint16_t size)
{
    uint16_t i, chksum1 = 0, chksum2 = 0;
    if((data[0] == 0xFD) && (data [1] == 0xFD))
    {
        for(i = 2; i <= size-3; i++)
            chksum1 += data[i];
        chksum2 = (uint16_t)(data[size-1] << 8) | (uint16_t)(data[size-2]);
        if (chksum1 == chksum2)
            return 1;
        else
            return 0;
    }
    else
        return 0;
}

int main(void)
{
    if (check_protocol(receive_data, receive_data_size) == 1) // Checksum
    {
        if (receive_data [2] == 0x02) // Protocol type
        {
            if(memcmp(&receive_data[4], current_id, receive_data[3]) == 0) // ID
            {
                uint16_t jump_size = 0, page = 0, param, param_size, r_pos;
                uint8_t flag_check_func = 1, BGCP_func;

                r_pos = 4 + receive_data[3];
                r_pos += 1 + receive_data[r_pos]; // Position in array where FUNC block begins
                // FUNC and DATA
                for(; r_pos < receive_data_size - 2; r_pos++)
                {
                    // Special commands
                    param_size = 1;
                    // New function number
                    if((flag_check_func == 1) || (receive_data[r_pos] == BGCP_CMD_FUNC))
                    {
                        if (receive_data[r_pos] == BGCP_CMD_FUNC)
                        {
                            r_pos++;
                            flag_check_func = 0;
                            BGCP_func = receive_data[r_pos];
                            if (BGCP_func != BGCP_FUNC_RESP) // If the function number is not supported
                                break;
                        }
                        continue;
                    }
                    // New lead byte value for parameter numbers
                    else if (receive_data[r_pos] == BGCP_CMD_PAGE)
                    {
                        page = receive_data[++r_pos];
                        continue;
                    }
                    // New parameter size value
                    else if (receive_data[r_pos] == BGCP_CMD_SIZE)
                    {
                        param_size = receive_data[++r_pos];
                        r_pos++;
                    }
                    // If the parameter is not supported
                    else if(receive_data[r_pos] == BGCP_CMD_NOT_SUP)
                    {
                        r_pos++;
                        // Processing of non-supported parameters
                        param = (uint16_t) (page << 8) | (uint16_t)(receive_data[r_pos]);
                        switch (param)
                        {
                            case 0x0001:
                            break;
                            case 0x0002:
                            break;
                        }
                        //
                        continue;
                    }
                    //
                    jump_size = param_size;
                    // Processing of supported parameters
                    param = (uint16_t) (page << 8) | (uint16_t) (receive_data[r_pos]);
                    switch (param)
                    {
                        case 0x0001:
                        State_Power = receive_data[r_pos+1];
                        break;
                        case 0x0002:
                        State_Speed_mode = receive_data[r_pos+1];
                        break;
                    }
                    //
                    r_pos += jump_size;
                }
                //
            }
        }
    }
}